The present invention relates to the manufacture of multi-ply laminated structures and, more specifically, to laminated structures incorporating a coupon or card that may be separated from the structure.
Coupons, ID cards, and membership cards, are often circulated or distributed via direct mail, personal delivery, public display modules, etc. Frequently, it is advantageous to secure these labels, coupons, or cards to a carrier sheet within the mailing, delivery package, or display module. In many instances, when the card or label is removed from the carrier sheet, an adhesive residue remains on the card. In other cases, the card or label lacks structural integrity, is difficult to remove from the carrier or fails to remain adhered to the carrier. In still further cases, the card and carrier sheet are bulky and difficult to handle. In addition, the various designs associated with conventional multi-ply laminated structures require manufacturing processes of significant complexity. Accordingly, there is a need for an improved method and means by which a label, card, or coupon may be circulated or distributed.
This need is met by the present invention wherein an improved laminated product, an improved laminating adhesive, and a method of manufacturing a laminated product are provided.
In accordance with one embodiment of the present invention, a laminated product is provided comprising a carrier sheet, a polymeric film ply, a card ply, and a radiation-curable laminating adhesive. The carrier sheet includes a first major surface, a second major surface, and at least one cut-out portion formed therein. The cut-out portion extends from the first major surface to the second major surface. The polymeric film ply is secured to the second major surface of the carrier sheet and extends over the cut-out portion to define an exposed ply portion aligned with the cut-out portion. The card ply is positioned within the cut-out portion. Either the film ply, the card ply, or both, are transparent to electromagnetic radiation.
The radiation-curable laminating adhesive is positioned to secure the card ply to the exposed ply portion. The laminating adhesive comprises a bonding agent, a monomer, an oligomer, a tackifier, and a photocatalyst. The bonding agent is present in a quantity sufficient to improve the bonding characteristics of the adhesive composition. The monomer is present in a quantity sufficient to (i) increase the flexibility of the adhesive composition, and (ii) increase the tendency of the adhesive composition to release substantially cleanly from a surface to which it is bonded. The oligomer is present in a quantity sufficient to increase the dimensional stability of the adhesive composition. The tackifier is present in a quantity sufficient to increase the uncured tack of the adhesive composition. The photocatalyst is present in a quantity sufficient to increase the tendency of the adhesive composition to cure upon exposure to electromagnetic radiation.
Preferably, where the film ply and the card ply are substantially impervious to water vapor, the laminating adhesive comprises a substantially 100% solids adhesive, whereby water need not be driven out of the adhesive to cure the adhesive. The laminating adhesive may comprise an adhesive selected so as to form a peelable bond with the card ply upon curing and a residual ply with the film ply upon curing, whereby the card ply may be removed from the laminated product substantially free of residual laminating adhesive. Further, the laminating adhesive is preferably composed such that, prior to curing, it is dimensionally stable upon application of a compressive force across the film ply, the laminating adhesive, and the card ply. Preferably, the film ply, the card ply, and the laminating adhesive form a cured laminated product defining a flexible laminated bond, wherein the flexible laminated bond is stable beyond a flexion characterized by a predetermined radius of curvature. The film ply may be secured to the carrier ply with a water-based mounting adhesive. Alternatively, the film ply is secured to the carrier ply with the laminating adhesive.
The respective thicknesses of the card ply, the film ply, and the adhesive layer are selected so as to define a substantially uniform product thickness across the laminated product. The card ply may be characterized by a thickness of about 0.008xe2x80x3, the film ply may be characterized by a thickness of about 0.001xe2x80x3, and the carrier ply may be characterized by a thickness of about 0.0095. Preferably, a periphery of the cut-out portion is reduced in thickness relative to a remainder of the carrier sheet to at least partially accommodate for the thickness of the film ply.
Where the back card face includes printed indicia, the laminating adhesive is preferably comprised of materials that cure to form an optically transparent adhesive ply. Further, the film ply is selected to be optically transparent such that the printed indicia are visible through the film ply and the optically transparent adhesive ply. Finally, the laminating adhesive and the printed indicia are preferably selected such that, upon contact of the laminating adhesive with the printed indicia, the respective compositions of the printed indicia and the laminating adhesive remain substantially independent, whereby the printed indicia retain a precise visual image upon contact of the laminating adhesive with the printed indicia.
Preferably, the polymeric film ply comprises an optically transparent monolithic film ply and the laminating adhesive is comprised of materials that cure to form an optically transparent adhesive ply. The card ply preferably comprises a substantially rigid polymeric planar ply.
In accordance with yet another embodiment of the present invention, a laminated product is provided comprising a carrier sheet, a polymeric film ply, a polymeric card ply, and a radiation-curable laminating adhesive. The film ply and the card ply are substantially impervious to water vapor. The laminating adhesive comprises an adhesive selected so as to form a peelable bond with the card ply upon curing, whereby the card ply may be removed from the laminated product substantially free of residual laminating adhesive. Further, the laminating adhesive comprises an adhesive selected so as to form a residual bond with the film ply upon curing, whereby residual laminating adhesive is present upon the film ply upon removal of the card ply from the laminated product. Finally, the laminating adhesive comprises a substantially 100% solids adhesive, whereby water need not be driven out of the adhesive to cure the adhesive.
The laminating adhesive is preferably comprised of a bonding agent, a monomer, an oligomer, a tackifier; and a photocatalyst. The bonding agent is present in a quantity sufficient to improve the bonding characteristics of the adhesive composition. The monomer is present in a quantity sufficient to increase the flexibility of the adhesive composition, and increase the tendency of the adhesive composition to release substantially cleanly from a surface to which it is bonded. The oligomer is present in a quantity sufficient to increase the dimensional stability of the adhesive composition. The tackifier is present in a quantity sufficient to increase the uncured tack of the adhesive composition. The photocatalyst is present in a quantity sufficient to increase the tendency of the adhesive composition to cure upon exposure to electromagnetic radiation.
In accordance.with another embodiment of the present invention, a method of lamination is provided comprising the steps of: (i) providing a carrier sheet including a first major surface and a second major surface, wherein the carrier sheet includes at least one cut-out portion formed therein, and wherein the cut-out portion extends from the first major surface to the second major surface; (ii) securing a polymeric film ply to the second major surface of the carrier sheet, wherein the film ply extends over the cut-out portion to define an exposed ply portion aligned with the cut-out portion; (iii) positioning a radiation-curable laminating adhesive to secure a card ply to the exposed ply portion; and (iv) directing curing radiation at the laminating adhesive through at least one of the film ply and the card ply such that the card ply is releasably bonded to the film ply.
The laminating adhesive is preferably positioned to secure the card ply to the exposed ply portion by applying a film of the laminating adhesive to the film ply. Typically, the film of the laminating adhesive is exclusively applied to the exposed ply portion of the film ply, the film ply is secured to the carrier sheet with a mounting adhesive applied to a periphery of the cut-out portion, and the laminating adhesive is positioned after application of the mounting adhesive. Alternatively, the laminating adhesive may be positioned to secure the film ply to the carrier sheet. The curing radiation may be directed through the film ply, the card ply, or both.
The method of lamination may further comprise the step of reducing the thickness of the carrier sheet, such that, upon creation of the cut-out portion, a periphery of the cut-out portion is characterized by a reduced thickness. Alternatively, the thickness of merely a periphery of the cut-out portion may be reduced. Preferably, the method of lamination further comprises the step of reducing the thickness of the carrier sheet to accommodate for the thickness of the film ply and the step of reducing the thickness of the carrier sheet is executed after the film ply is secured to the carrier sheet.
In accordance with yet another embodiment of the present invention, an adhesive composition is provided comprising a bonding agent, a monomer, an oligomer, a tackifier, and a photocatalyst. The bonding agent is present in a quantity sufficient to improve the bonding characteristics of the adhesive composition. The monomer is present in a quantity sufficient to (i) increase the flexibility of the adhesive composition, and (ii) increase the tendency of the adhesive composition to release substantially cleanly from a surface to which it is bonded. The oligomer is present in a quantity sufficient to increase the dimensional stability of the adhesive composition. The tackifier is present in a quantity sufficient to increase the uncured tack of the adhesive composition. The photocatalyst present in a quantity sufficient to increase the tendency of the adhesive composition to cure upon exposure to electromagnetic radiation.
The adhesive composition may further comprise a photo-catalytic curing synergist present in an amount sufficient to decrease the curing time of the adhesive composition upon exposure to electromagnetic curing radiation. The curing synergist may comprise an amine. The adhesive composition may further comprise a flowaid agent present in a quantity sufficient to improve the wet-out characteristics of the adhesive composition.
Accordingly, it is an object of the present invention to provide an improved laminated product, an improved laminating adhesive, and an improved method of manufacturing laminated products. Other objects of the present invention will be apparent in light of the description of the invention embodied herein.